Birefringence refers to a phenomenon that a beam is separated into two beams refracted along different directions in an anisotropic crystal after incidence, and the two separated beams are linearly polarized lights with vibration directions vertical to each other. Birefringence of an optical polymer mainly includes orientation birefringence and photoelastic birefringence. Here, photoelastic birefringence is birefringence generated by elastic deformation of a polymer. In use of an optical member, if the temperature of the optical member changes, then the volume of the optical member will shrink, and therefore elastic deformation occurs in the material and the elastic deformation of the material will lead to photoelastic birefringence.
In production and use of a liquid crystal display panel, it will be subjected to the action of stress to allow the liquid crystal display panel to generate elastic deformation. Therefore, the photoelastic birefringence index of the liquid crystal display panel will change so as to result in the generation of the phenomenon of light leakage.
In the prior art, it is typical to reduce the birefringence of an optical resin by changing the orientation of the main chain of the resin material from which a polarizer or a protective layer of a liquid crystal display panel is formed, or by eliminating elastic deformation. However, this will greatly reduce production efficiency.
Therefore, how to eliminate optical birefringence by a simple method becomes a technical problem urgent to be solved in the art.